TY  - BOOK
AU  - Lavrentev, Mikhail Alekseevich,
TI  - Variational methods for boundary value problems for systems of elliptic equations
SN  - 627
U1  - 515.64 
PY  - 1963///
CY  - Groningen
PB  - P. Noordhoff
KW  - Calculus of variations
ER  -